/*
This file is part of libhttpserver
Copyright (C) 2011-2025 Sebastiano Merlino
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
USA
*/
// minimal_https_psk.cpp - TLS with pre-shared keys instead of certificates.
// The PSK lookup callback is invoked once per handshake to resolve a
// client-supplied identity into the shared secret.
#include
#include
#include
#include
#include
// PSK database loaded from environment variables at startup.
//
// SECURITY NOTE: Never hardcode PSK keys in source code (CWE-321 / CWE-798).
// The values below are placeholders. For illustration; production must:
// - Load keys from environment variables, a key file, or a secrets manager.
// - Use at least 128 bits of cryptographically-random key material.
// - Rotate keys regularly.
//
// Example environment setup before running:
// export PSK_CLIENT1=0123456789abcdef0123456789abcdef
// export PSK_CLIENT2=fedcba9876543210fedcba9876543210
// ./minimal_https_psk
static std::map build_psk_database() {
std::map db;
const char* k1 = std::getenv("PSK_CLIENT1");
const char* k2 = std::getenv("PSK_CLIENT2");
if (!k1 || !k2) {
std::cerr second;
}
return "";
}
int main() {
// The priority string locks to TLS 1.2 because GnuTLS external PSK in
// TLS 1.3 requires a different mechanism (session-ticket-based resumption).
// Port 8443 signals HTTPS semantics by convention.
httpserver::webserver ws{
httpserver::create_webserver(8443)
.use_ssl()
.cred_type(httpserver::http::http_utils::PSK)
.psk_cred_handler(psk_handler)
.https_priorities("NORMAL:-VERS-TLS-ALL:+VERS-TLS1.2:+PSK:+DHE-PSK")};
ws.on_get("/hello", [](const httpserver::http_request&) {
return httpserver::http_response::string("Hello, World (via TLS-PSK)!");
});
ws.start(true);
return 0;
}